2 sentences

1. 他们都哈哈大笑起来。

   tā​men dōu hā​hā dà​xiào qi​lai.

   They all burst out laughing.

   Source: Tatoeba

2. 他听了那个笑话后哈哈大笑。

   tā tīng le nà​ge xiào​hua hòu hā​hā dà​xiào.

   He burst into laughter after hearing that joke.

   Source: Dong Chinese Dictionary